Ovidiu Cristea, Florențiu Deliu, Nicolae Badara and Octavian Tarabuta
Communications applications in the underwater environment have recently developed a considerable development due to the demand for underwater research with Robot Underwater Vehicle (ROV). The most important aspects addressed by researchers are related to the speed and distance of data transmissions. In most cases, this data signal may be electromagnetic, optical or acoustic. The first two cases have limitations on the distance of the communication channel due to signal attenuation. That is why the acoustic field can be considered the favorite in this choice. In this case, the limitations of use are given by the acoustic field propagation, which depends on the temperature, salinity and pressure of the underwater environment and the result is the variation of the propagation speed. The influence of frequency on attenuation and reverberation are important factors limiting the use of the acoustic field. Based on these considerations, the paper presents an experimental transceiver model of data transmission using Frequency Shift Keying (FSK), modulation with phase discontinuity for transmitting and receiving commands at the speed of 2kbits / s
The paper analyzes the operation of electric power subsystem consisting of the naval marine wind turbine, the synchronous generator and the electric accumulators at linear and exponential variations of wind speed. The management system is analyzed using various functions of wind speed variation. This subsystem requires to capture the wind energy with maximum efficiency, so a diesel engine and a synchronous generator subsystem can be used only as a complementary source of energy.